1. Technical Field
The present invention relates to an oscillator, an electronic apparatus, and a vehicle.
2. Related Art
A temperature-compensated crystal oscillator (TCXO) has a quartz crystal resonator and an integrated circuit (IC) for oscillating the quartz crystal resonator, wherein the IC compensates (performs temperature compensation on) the deviation (frequency deviation) from the desired frequency (nominal frequency) of the oscillation frequency of the quartz crystal resonator in a predetermined temperature range, and thus, high frequency accuracy can be obtained. Such a temperature-compensated crystal oscillator (TCXO) is disclosed in, for example, JP-A-2014-53663.
Further, the temperature-compensated crystal oscillator is high in frequency stability, and is therefore used for communication equipment and so on for which high performance and high reliability are required.
The frequency signal (the oscillation signal) output from the oscillator includes phase fluctuation. Among the phase fluctuation of the frequency signal, the fluctuation with a frequency lower than 10 Hz is called wander. In ITU-T Recommendation G.813, there is defined the wander performance in the state in which the temperature is constant.
However, in the practical usage, it is difficult to make the oscillator operate under the environment in which the temperature is kept constant. For example, even if the oscillator is compliant with ITU-T Recommendation G.813, there is a possibility that sufficient performance cannot be exerted under a severe temperature environment such as the case in which the oscillator is used for a car navigation system or a variety of vehicular gauges, and the case in which the oscillator is incorporated in a device, the temperature of which changes rapidly due to the action of a fan or the like.